Watch with electronic buzzer

ABSTRACT

An improved electronic alarm watch is disclosed having improvements in the structure and arrangement of the accoustically alarming vibrator employed in the alarm mechanism thereof. The improved watch of the above type comprises a watch casing, wherein is located a watch movement, alarm switch controlled thereby, alarm oscillator circuit and a battery source adapted for energization thereof. An oscillatory membrane is fixedly attached with a piezo-electric or electro-strictive element which is electrically connected through the switch with the oscillator circuit and the battery for being energized therefrom, the membrane being arranged in a space defined by and between a perforated back cover and the watch movement.

United States Patent m1 Iinuma 131 .hssignee: Citizen Watch Company Limited,

Tokyo, Japan [221 Filed: Mar. 22, 1972 [2!] Appl. No.: 237,137 V [30] Foreign Application Priority Data Mar. 30. i97l Japan................................ 46118984 3,638,418 2!!972 Spedini $857.5

' Primary Examined-George H. Miller. Jr.

Attorney-John C. Holman et al.

[57] ABSTRACT An improved eiectronic alarm watch is disclosed having improvements in the structure and arrangement of the accoustically alarming vibrator employed in the alarm mechanism thereof. The improved watch of the above type comprises a watch casing, wherein is located a watch movement, alarm switch controlied [52 US. cl. 58157.5, 58/90 R y. alarm oscillator circuit and a some [51] Int. Cl. G044: 21/34 adapted for mergilaiiml therwf- All y mail [58} Field of Search 58/19 A, 19 B. :0, brain is fixedly attached with a view-decide or elw 53/2], 515,90 R tro-strictive element which is electrically connected through the switch with the oscillator circuit and the [56] References Cit d battery for being energized therefrom, the membrane UNITED STATES PATENTS being arranged in a space defined by and between a 3577.876 spam MM mmmm n 58 '51s perforated back cover and the watch movement. 3,462,943 8/1969 Spldini et al. 58157.5 18 Claims, 9 Drawing Figures 22 9f 27 27a 27 27 22a 23 24 25 2713 27 iE a: fi m e; 2% 923a; 132- r 3 Jan .l x x b A 4 m W V v 13a 13 10a 12 10a BACKGROUND or The mvsrrnoiv This invention relates to improvements in and relating to electronic alarm watches; more specifically, it is concerned with improvements in the structure and arrangement of the acoustically alarming vibrator of the alarm mechanism employed in such watches.

Various and numerous mechanical alarms have been broadly used in the field of alarm watches. it is, however, a grave drawback that the mechanical alarm conventionally used operates substantially at a rather lower frequency field than about 1,000 cycles per second, thus representing a rather low loudness level in comparison with a substantial amount of the fed energy for the alarm service. Although consumers are nowadays aquainted with tones of electronic sense, especially with the pitch and timber thereof, by virtue of rapidly developing and broadly marketed electronic timepieces, the mechanical alarm can not meet with such modern demands by consumers. A further drawback inherent in the conventional mechanically alarmed watches resides in a gradual attenuation of the loudness during continued service of the alarm device, thus generally speaking, substantially no effective alarming caution being felt by the watch bearer during the latter half of the alarm service. With such mechanical alarm, the watch bearer must wind up the power spring of the alarm device almost every time after a practical service of the device. in addition, sounds of variable tone sense can not be delivered from the mechanical alarm device, because it delivers only a monotoned acoustic alarm signal.

in consideration of the above conventional drawbacks inherent in mechanical alarm devices, it has already been proposed to tit an electronically operated buzzer energized by current horn a battery.

Almost all prior electronic alarms for use with watches are, however, designed and arranged to be of the electrodynamic type employing coils and permanent magnets cooperating therewith, resulting in a substantially large sized device, especially large dimen sions for the buzzer-operating circuit and the acoustic converter. in the conventional arrangement of the abovedtind, the watch movement and the electronic buzzer are arranged generally in a common plane and parallel to each other, thus the overall assembly has larger outer dimensions than otherwise; frequently a certain irregular outline configuration must be employed, disturbing thereby the desired appearance and device. in addition, provision of the permanent magnet means provides disadvantageous effect upon the time base vibrator and thus, there are problems which require to be solved.

in the conventional arrangement the watch movement and electronic buzzer in parallel to each other in ;a common plane, they must be encased in separate alarming function. Such an arrangement will naturally have a highly complex overall structure and the number of the related parts must be increased which procompactness of the watch assembly including the alarm 2 duces in turn a corresponding increased manufacturing cost.

SUMMARY OF THE INVENTION it is therefore a main object of the invention to provide an electronically alarmed compact watch having substantially the same outline dimensions as other conventional watches of the waterproof structure, with all the necessary components of the alarmdevicc arranged to in a self-contained mode.

For this purpose, the invention starts from a substantially conventional watch which comprises a watch casing, wherein is located a watch movement, alarm switch controlled thereby, alarm oscillator circuit and IS a source battery adapted for energization thereof.

According to the main feature of the present invention, a membrane is fixedly attached with a piezoelectric or electro-strictive element electrically connected through said switch with said oscillation circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement. The membrane, together with said piezoelectric or electrostrictive element and a membrane carrier, is electrically so connected with the alarm oscillator circuit as to be easily detachable therefrom, and thus equally with the watch unit. The membrane is preferably made of a conductive metal foil. However, when necessary, it can be made from a plastic film or sheet. in this case,

the electric connection is made directly with the element, thus without the intermediary of the membrane per se.

BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the invention will become more apparent from the following detailed description of the invention with reference to the accompanying drawings illustrative of several preferred embodiments of the invention.

FIG. I is an axial sectional view of a preferred first embodiment of the invention, substantially taken along a section line H shown in FIG. 2, wherein, however, an alarm oscillator circuit block is only partially sectioned and a main movement block and a'battery block are shown only in their outline configuration.

FIG. 2 is a bottom plan view of the watch unit shown in FIG. 1 wherein, however, the back cover and the oscillatory membrane are broken away for desplay of inner working parts.

H6. 3 is part of a perspective view of the alarm oscilla'tor membrane attached fixedly with an electrostrictive element, said membrane being shown as mounted at its periphery by a membrane carrier formed in this embodiment into a ring.

FIG. 4 is a schematic and illustratiye view, demonstrating the power transmission mode as well as the 7 electric connection mode among several main working parts employed in the foregoing first embodiment of the invention.

ing first embodiment and taken out from the watch unit showninFlGS. landZ. f

FIG. tilis substantially similar view to FIG. 1, illustrating, however, a second embodiment of the invention and demonstrating those which are different from those FIG. 5 is a schematic plan view, shown on a reduced I scale, of the watch movement employed in the foregospecifically described hereinafter.

H6. 7 is part of an axially sectional view of a preferred third embodiment of the invention, shown, however, in a substantially similar way to FIG. 1, yet on a somewhat enlarged scale.

FIG. 8 is a similar view to FIG. 7, showing, however, a preferred fourth embodiment of the invention.

FIG. 9 is a part of a perspective view of a back cover employed in the fourth embodiment shown in FIG. 8, wherein, however, said back cover is sectioned partially.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to.FlGS. 1-5, the first embodiment will be described hereinbelow in detail.

Numeral 1 generally denotes a watch movement in its broadest sense and comprises a conventional pillar plate 2, appearing only partially and mounting several main working parts, as will become more clear as the description proceeds.

Numeral 3 represents a mercury battery of known structure and detachably mounted within said movement 1. In the present embodiment, this battery 3 is adapted to feed an electronically operated timepiece movement and a buzzer with current, as will be more A battery mount 4 made of an insulating material and fixed with said pillar plate 2 mounts the battery block 3 in position, a pressure spring 5 detachably attached by means of set screw 5a and 5b to the plate 2 holding the battery block in position from upper of FIG. 1 with a slight resilient pressure applied thereto.

Numeral 6 represents only schematically an electronic drive circuit of conventional structure and molded into a block with a synthetic resin and detachably attached to pillar plate 2 by means of set screws 6a, 6b and 6c. This drive circuit is adapted for driving electro-dynamically a conventional time base oscillator, preferably in the form of a balance wheel motor, a turning fork, a turning lead or the like, as commonly known per se. The drive circuit is electrically connected through the plate 2 and lead wire means, not shown, to the battery 3, as known per se.

Numeral 8 represents a main working parts block including the conventional watch gear train andyomprising a balance wheel 8a which is driven electromagnetically from said electronic drive circuit 6, said gear train, although not shown specifically by virtue of its very popularity, being mounted by and between the plate 2 and bridges 8:; 8} which is fixedly attached thereto by means of a plurality of set screws 8b; 8c and 84. It should be mentioned at this stage that the term "block" in this case is used only for convenience so as to discriminate the gear train as a whole from other working parts of the watch and it does not constitute a practical block.

Numeral 9 represents an alarm oscillator circuit block comprising transistor(s), condenser(s), resistors and the like which constitute an electronic oscillator and compacted into a molded block 9a by a synthetic resin such as an epoxy base resin, and a transformer 9b electrically connected with said oscillator and with a piezoelectric or .electro-strictive. element 25. This transformer 9b serves for elevating the output from the oscillator in its voltage so as to adapt for oscillation of the element 25as will become more apparent as the description proceed 'lhis circuit block 9 is fixedly, yet

easily detachably attached to the plate 2 by means of several set screws 9:; 94'.

I Numeral l0 denotes a conventional time-indicating dial bearing on its outer surface with known timeindicating symbols although not shown. for the demonstration of time by cooperation with time-indicating hands l4, l5 and 16. This dial 10 is detachably mounted on the plate 2, although the attaching means have been omitted from the drawing only for simplicity and convenience. It should be noted, however, that a conductive strip 10a is provided in a concentric ring on the inside surface of the dial 10, and preferably, by the print circuit technique.

Battery mount plate 4 is formed with a perforation 4b in which a U-shaped contact spring 4a is kept in position in somewhat projecting manner. In the assembled position shown, this contact spring 4a serves as conducting means between said battery 3 and conductive strip 10a.

Numeral 1! denotes a conventional cannon wheel and a conventional unlocking wheel 12 is rotatably mounted thereon. An unlocking spring 13 is provided as shown, especially in FIG. 1, the root end of this spring 13 is fixedly mounted on a terminal 9c 'of said oscillator circuit block 9 by means of a set screw 13a. The free end 13b of spring 13 is kept in pressure contact with the upper surface of the wheel 11, so as to urge resiliently the latter to move axially downwards when seen in FIG. 1. A projection or contact portion 130 is formed on the spring 13 at an intermediate point between the ends thereof. thus providing a possibility 'to establish an electrical cooperation with conductive strip on the dial it). In this way, an unlocking switch 30 (FIG. 4) is constituted by the combination of cannon wheel I], unlocking wheel 12 and unlocking spring 13.

Cannon wheel 11 is formed with three projections lla having mutually different radial lengths measured from the center of the wheel 11. Only for simplicity, however, these projections I la is represented as if they are single in FIG. 1. in a corresponding way, unlocking wheel 12 is formed with three different perforations 122 which are, however, represented as only one as a representative thereof for simplicity.

Although not shown, there is provided a conventional alarm time setting device manually operable by a main winding stem 40, or alternatively by an auxiliary second stem, not shown, as the case may be, for setting the unlocking wheel 12 to a desired alarm time. For indication of the alarm time, the unlocking wheel 12 is fitted with alarm hand 14. This hand 14 is press-fit on the boss of the wheel 12.

As commonly known, the cannon wheel 11 performs a complete revolution per 12 hours by receiving motion from the gear train of the watch. When the alarm time comes, the projectons on the wheel ll are brought into engagement with corresponding and mating perforations and 12a on the wheel 12, thereby the former wheel 1 1 being urged to move downwards in FIG. 1 and nearer towards the latter wheel 12, so as to establish an electrical connection between the contact portion on spring contact 13 and the conductive strip 100 on dial 10. r

Hour hand 15 is press-fit on the boss of cannon wheel 11 as conventionally. Minutehand 16 is attached on Numeral 18 represents a case central body which mounts detachably a transparent plastic cover 19 used in this specific embodiment in place of a crystal, a ringshaped tension spring 190 urging the cover from inside to-expand resiliently outwards, so as to establish a tight and sealed connection between the cover and the case center body.

A ring-shaped movement positioner 20 is positioned along its substantial peripheral length between plate 2 and case central body 18. A sealing ring 21 is inserted between the case central body 18, and a membrane carrier 22 having a ring web projection 22a on which the periphery of a oscillatory membrane 24 is fixedly attached by means of adhesive. The carrier 22 is formed with an inwardly projecting arm 22b and provided with an insulator sleeve 230 which holds firmly a combined stationary contact and terminal 23. On the inside surface of the membrane 24, a piezo-electric or electrostrictive element 25 is firmly attached by glueing or the like conventional attaching means, a conductive lead 26 connecting electrically the contact and terminal 23 with the element 25.

The molded alarm oscillator circuit block 9 is provided at its output side with a conductive spring arm 9] which is normally kept in pressure and conductive contact with the member 23 when the block 9 and membrane carrier 22 have have been assembled together in position as seen clearly from FIG. 1. The root end of said spring ann 9f is emoodded rigidly in the mass of the molded block 9.

Membrane carrier 22 is formed at its periphery with an outwardly extending positioner projection 22c which is kept in engagement with an inwardly directing recess 18b formed on case center body 18. In the assembled position shown in FIGS. 1 and 2 and thus, under the engaging position of these positioning means 18b; 22c, the spring arm 9] is kept in pressure contact with the matching contact and terminal 23 as above referred to.

In the first embodiment so far shown and described, the oscillatory membrane 24 is made of aluminum foil having a thickness of about 50 100 microns and glued to the upper surface stem 22a as was referred to briefly hereinbefore, yet in a conductive way therebetween. In order to realize such conductive attachment, the glueing agent per so may be made conductive in such a way that pulverized carbon is mixed with the agent- Or alternatively, the membrane is subjected to a high axially compressive pressure upon glueing thereof to the carrier, even when the glueing agent per se is of non-conducting nature. The element 25 is glued to the inner surface of the membrane, preferably at its center as shown, so as to establish an electric connection therebetween.

When the element 25 is made piezoelectric, it is prepared by way of example from Rochelle Salt, ammo nium hydrogen phosphate, lithium sulphate, dipotassium tartrate. On the other hand, when the element is made electro-strictive, it is prepared by way of example from barium titanate, PbZrTiO; or the like. Consequently, the element 25 comprises a substrate 25a consisting of anyone of the aforementioned materials and having electrodes 25b; 25c deposited on both surfaces.

In the present embodiment, one electrode 25!; is glued to the membrane 24 as briefly referred to hereinbefore.

while the remaining electrode 25c is fused to the end of lead 26. This mode is more specifically seen frr FIG. 3.

Numeral 27 denotes a back cover which is form with a number of projections 270 over its substantia whole area so as to prevent a tight contact with t wearer's skin, while the remaining base area 27b fonned with a number of perforations 27: for releasi1 acoustic alarming signals from inside of the watch in the open atmosphere.

At the outside periphery, the back cover 27 is form: with several recesses 274' for receiving operating cm of a turning tool. Further, the back cover 27 is form: on its peripheral surface with male screw threads 21 adapted for engagement with mating female scre threads 180 formed on the case central body 18. Ft attachment of the back cover 27, it is screwed fror upper-into thebody 18 by use of the turning tool.

It will be clear from the foregoing that the interic space of the watch as defined by membrane 24, carrie 22 thereof, sealing ring 21, case central body 113 am transparent and plastic front cover 19 is kept effec tively in a sealed condition for prevention of the inva sion of moisture from outside into the inside of thr watch. It should be noted in the present specifc em bodiment that the oscillatory membrane 24 acts as r from of seal by defining means for providing the afore' mentioned sealed-inchamber which preserves the mair working constituents including the watch movement in an effectively sealed way.

As an example, if itisassumed that the membrane 24 is made of aluminum having a thickness of microns, then a sealed-off condition of the said sealed chamber under a static pressure corresponding to about 10- meter depth in water is assured. The normally required waterproof requirement can be satisfied by use of such an alarm watch structure.

The operation of the first embodiment of the watch alarm according to the first embodiment of the present invention will be described in detail, additionally by reference to FIG. 4.

The unlocking wheel 12 is set to a certain selected time point by manipulating the main or auxiliary winding stern, as was briefly described hereinbefore.

Current isfed from battery 3 through several conductive parts to electronic drive circuit 6. More specifically, the positive side of battery 3 is connected through pressure spring 5, pillar plate 2 and a certain conductor, not shown, to the positive inlet terminal, not shown, of the drive circuit 6. 0n the other hand, the negative side of battery 3 is connected spring 40, conductive strip and a certain conductor, not shown, to the negative inlet terminal, not shown, of the drive circuit 6, as conventionally. ln this way, the watch gear train, not shown, is driven and cannon wheel ll is caused to rotate continuously as briefly referred to hereinbefore.

When the alarming time comes, projections llc on the wheel 11 are brought into engagement with correspending perforations 12a in the wheel 12 so that the former wheel 11 is urged to move downwards in FIG. 1 under the action of unlocking spring 13 and the intermediate contact portion l3c thereof is brought into pressure contactwith the conductive strip 10a, thereby the unlocking switch 30 being turned to on. in this way,

current is supplied from battery 3 to alarm oscillator circuit 9. More specifically, a circuit is closed through battery 3, contact conductive strip 10 on 7 dial l0, unlocking spring 13, oscillator circuit 9 and pi!- lar plate 2.

When the oscillator circuit 9 starts'to-oscillate in this way at a certain constant frequency, preferably selected between 1,000 and 3,000 cycles per second, the oscillatory output voltage therefrom is conveyed through the elevating transformer 9b to the element 25 which is thus kept in oscillation together with its carrying membrane 24. Practically, the transformer 9b constitutes a member of the circuit 9 and serves for transmitting the oscillative electric drive energy from the oscillator circuit to the element 25. By the oscillative movement of the membrane 24, a corresponding acoustic signal is generated and will be delivered from the interior of the watch casing comprising the members 18, 19 and 27 into the open atmosphere through the perforations 27c of the back cover 27.

Next, the second embodiment of the invention will be described hereinbelow by reference to FIG. 6.

In this embodiment, same or similar parts to those which have been employed in the foregoing embodiment are denoted with respective same reference numerals added each with 100, for easy comparison and understanding and regardless of occasionally appearing minor configurational difference.

In this embodiment, the watch movement is of the similar structure and arrangement as before. A spring arm 109f acting as a contact or terminal is equally provided for the alarm oscillator circuit block 109 and embedded in the molded mass by its root end as before. 118 denotes a case central body, 120 a movement positioner and 121 a sealing ring. Membrane carrier 122 of a conductive material is formed substantially into a circular disc which is, however, formed with a ring projection 1220 at a proximity to the outer periphery of the disc, said ring projection being formed with a number of radially directing, preferably equally spaced radial openings 122c acting similarly as the perforations 127C for the delivery of the acoustic alarm signal. A contact piece 123 is mounted fixedly in an insulator sleeve 1230 which is firmly held in the circular disc portion of said carrier 122 at a position corresponding to the acting end of the spring arm 109]. The oscillatory membrane 124 is glued at its peripheral area to the upper surface of the ringprojection 122a in a conductive way as before. The membrane 124 is attached firmly, preferably at its center, with a piezo-electric or electrostrictive element 125 by glueing in a conductive way as before, said element being electrically connected through a lead 126 with the contact piece 123 again as before.

Numeral 127 represents back cover which is formed with male threads 127e at its outer periphery for screw fitting thereof with the mating female threads 118a of ease central body 118. This back cover 127 is formed further with a number of radial openings 127v adapted for release of alarming sound signals.

Water-proofness of the watch is attained by the combination of membrane carrier 122, sealing ring 121, case central body 1 l8 and a plastic'or glass cover which may be similar to that shown at 19 in the first embodiment, although not shown. Therefore, itwill be seen from the foregoing description that in the present embodiment, the membrane 124 has nothing to do with the realization of the water-proofness contrary to that shown at 24 in the first embodiment.

parison, regardless of occasional minor configurational Numeral 208 represents a main working parts block containing the regular watch gear train. This block 208 does not constitute a real block, as was referred to similarly in the first embodiment and the nomination of the block" is only for the convenience of description and graphical representation. Numeral 210 represents I dial, 209 an alarm oscillator circuit block, having a spring arm 209]; the root end of which is firmly embedded in the molded mass of the block. Numeral 218 denotes the case central body and 221 represents a sealing ring. The back cover 227 is formed with a number of sounds releasing perforations 2270, although only one thereof is shown as a representative.

The back cover 227 is formed on its inside wall surface with a ring shoulder 2271' to which the oscillatory membrane 224 carrying the piezo-electric or electrostrictive element 225 is glued firmly at its peripheral zone.

An auxiliary inside cover 222 is pressed-on or glued to the inside wall of the back cover, was to define a chamber in which the membrane 224 is contained as shown. On the inside or lower surface of the inside cover 222, a conductive strip 223 is fixedly attached by glueing or the like conventional fixing means at a position substantially in registration with the conductive spring arm 209]. A lead 226 connects electrically the spring arm 209] with the piezo-electric or electrostrictive element 225 as before. For this purpose, the

lead 226 passes through a perforation 222d drilled Since the membrane 124 is exposed at its both an faces to the ambient atmosphere, it will not be subthrough the inside cover 222 which is made of aninsulating material such as plastic, rubber or the like.

A fixing screw ring 228 is provided for fixedly attaching the back cover 227 to the case central body 218, said ring 228 being formed for this purpose with male threads 2284 adapted for screw engagement with corresponding female threads 218a on the body 218. The ring 228 is provided with a plurality of recesses 228b, only one thereof being shown in FIG. 7 as a representative thereof for simplicity, adapted for engagement with a turning tool, not shown.

Water-proofness of the watch is assured by the combination of membrane 224, back cover 227, sealing ring 221, case central body 218 and a glass or plastic cover 0: crystal, not shown.

The reason for the provision of screw ring 228 for attachment of back cover 227 to the case body 218 is for assuring the predetermined registration of the both conductive members 209f and 223 and for the prevention of unintentional turning of the back cover relative to the case body, or more specifically to the conductive spring arm 209].

Finally, referring to FIGS. 8 and 9, the fourth embodiment of the invention will be described hereinbelow in detail.

. In this embodiment, same or similar parts as employed in the first embodiment are denoted with respective same reference numerals. each being, however, added with 300 for easy comparison, irrespective of occasional minor configurational difference.

The oscillatory membrane 324 fitted tightly with a piezo-electric or an electro-strictive element 325 is attached tightly at its peripheral zone to a shoulder 3271' formed on the inside wall surface of a perforated back cover 327; an inside cover 322 made of an insulating material and fitted with a conductive strip 323 is press fit from inside onto the back cover 327. The element 325 and the conductive strip 323 is connected electrically by means of a conducting lead 326 which pmes through a perforation 322d drilled through the inside cover.

The back cover 327 is formed with a large concentric opening 327 and with a plurality of radical recesses 327g.

A secondary and auxiliary back cover element 331 is pressiit into the said concentric opening 3271:. For prevention of occasional and unintentional disengagement of the cover element 331 from the mating and receiving opening 327k. the element 331 is formed with an enlarged and resilient end ring 3310 acting as a kind of stop means. The overall diameter of the cover element 331 is so selected that the latter does not cover in any appreciable degree and that these recesses 329g act well for release of alarming sounds from inside of the watch unit into the open atmosphere therethrough, when such sounds are generated by oscillatory movement of the membrane 324.

Numeral 32th represents a sealing ring for keeping of a sealing connection between the members 320 and 327. A further sealing ring 321a is provided for keeping a sealed connection between the members 318 and 327.

it should be noted that in the present embodiment, the conductive strip 323 is formed into a concentric ring relative to the back cover 327, thus no specifically selected registration being unnecessary to establish an electric connection between the both conductive mernbers 323 and 309]. Thanks to this specific structure, the back cover 327 per se is formed with male threads 32?: for screw coupling with the case central body 318.

Water-proofness is assured by the combination of oscillatory membrane 324, back cover 327, sealing ring 322a, case central body 318 and a glass or plastic cover or crystal, not shown.

After establishment the electrical connection through the conducting lead 326 as in the aforementioned way, the passage opening 322d can be filled up with a certain filler material such as plastic resin, so as to maintain the water-tightness by the help of inside cover 322, should the membrane 324 be broken by occasional and unintentional application of an appreciably high pressure onto the membrane. This feature can also be applied tothe third embodiment shown in HQ.

The reason for the provision of the auxiliary back cover element 331 is to provide a possibility for cleaning and removal of dirty particles invaded from outside through said recesses 327g into the membranecontaining space of the watch unit and after provisional removal of the back cover element 331.

in the third and fourthembodiments, different from the first and second embodiments, the back cover attached with the membrane can be treated as a subunit in the assembly of the watch unit. Therefore, it will be seen that the assembly job can' be performed substan tially similarlywith the case of a non-alarmed watcl unit.

In any of the foregoing embodiments, the membrant and its carrier could be arranged in a substantially proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure is occasionallyapplied thereto.

When the oscillatory membrane is made of a plastic film or sheet, both electrodes of the piezo-electric or electrostrictive element are connected electrically through respective conductor leads with two contacts mounted or on the inside cover, as the case may be, and the input and output terminal of the alarm oscillator circuit are electrically connected with the said two stationary contacts. a

Similar connecting mode can be employed for the electrodes of the oscillatingly drive element and the terminals of the alarm oscillator circuit, as will be easily understood from the foregoing, when the back cover or the auxiliary back cover element is made of an insulating material such as plastics.

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. in a watch with an electronically driven alarm, the watch comprising in combination, a watch casing with a watch movement contained therein, an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing and a source battery adapted for energization of said oscillator circuit and contained within said casing, the alarm comprising an oscillatory membrane and a piezo-electric or electrostrictive element fixedly attached to said membrane and electrically connected through said switch with said oscillator circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and tightly supported at its peripheral area on a membrane carrier which is arranged between said back cover and said watch movement.

2. Alarm watch as set forth in claim 1 wherein said membrane, together with said piezoselectric or electrostrictive element and a membrane carrier, is electrically so connected with the alarm oscillator circuit as to be easily detachable therefrom, and thus equally from the watch unit.

3. Alarm watch as set forth in claim 1, wherein said membrane is made of a conductive metal foil,v

4. Alarm watch as set forth in claim I wheiein said membrane carrier acts as a part of water-proofing members of the watch unit.

5. Alarm watch as set forth in claim 1, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.

6. Alarm watch as set forth in claim I, wherein said membrane acts as a part of water-proofing members of the watch" unit. 1

7. Alarm watch as set forth in claim 6, wherein the membrane and its carrier or an inside cover member are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto.

8. in a watch with an electronically driven alarm. the watch comprising in combination of a watch casing, a watch movement contained therein. an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing, and a source battery adapted for energization of said oscillator circuit and contained within said casing, the alarm comprising an oscillatory membrane and a piezo-electric or electrostrictive element fixedly attached to said membrane and electrically connected through said switch with said oscillation circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and fixedly mounted at its peripheral zone by said back cover which is provided with a contact terminal connected through a lead with said element.

9. Alarm watch as set forth in claim 8, wherein said membrane, together with said piezoelectric or electrostrictive element and a membrane carrier, is electrically so connected with the alarm oscillator circuit as to be easily detachable therefrom, and thus equally from the watch unit.

10. Alarm watch as set forth in claim 8, wherein said membrane is made of a conductive metal foil.

1 1. Alarm watch as set forth in claim 8, wherein said membrane carrier acts as a part of water-prooting members of the watch unit.

12. Alarm watch as set forth in claim 8, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.

13. Alarm watch as set forth in claim 8, wherein said membrane acts as a part of water-proofing members of the watch unit.

l4. Alarm watch as set forth in claim 13, wherein the membrane and its carrier or an inside cover member are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto.

15. in a watch with an electronically driven alarm, the watch comprising in combination of a watch casing, a watch movement contained therein, an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing, and a source battery adapted for energization of said oscillator circuit and contained within said casing. the alarm comprising an oscillatory membrane and a piezo-electric or electrostrictive element fixedly attached to said membrane and electrically connected through said switch with said oscillation circuit and said battery for being energized therefrom? said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and made of a conductive metal foil, said element comprising a pair of electrodes and said watch being characterized by that one of said electrodes is conductively connected with said membrane.

l6. Alarm watch as set forth in claim 15, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.

17. Alarm watch as set forth in claim 15, wherein said membrane acts as a part of water-proofing members of the watch unit.

18. Alarm watch as as set forth in claim 17, wherein the membrane and its carrier or an inside cover memher are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto.

# i i t i 

1. In a watch with an electronically driven alarm, the watch comprising in combination, a watch casing with a watch movement contained therein, an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing and a source battery adapted for energization of said oscillator circuit and contained within said casing, the alarm comprising an oscillatory membrane and a piezo-electric or electro-strictive element fixedly attached to said membrane and electrically connected through said switch with said oscillator circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and tightly supported at its peripheral area on a membrane carrier which is arranged between said back cover and said watch movement.
 2. Alarm watch as set forth in claim 1 wherein said membrane, together with said piezo-electric or electro-strictive element and a membrane carrier, is electrically so connected with the alarm oscillator circuit as to be easily detachable therefrom, and thus equally from the watch unit.
 3. Alarm watch as set forth in claim 1, wherein said membrane is made of a conductive metal foil.
 4. Alarm watch as set forth in claim 1 wherein said membrane carrier acts as a part of water-proofing members of the watch unit.
 5. Alarm watch as set forth in claim 1, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.
 6. Alarm watch as set forth in claim 1, wherein said membrane acts as a part of water-proofing members of the watch unit.
 7. Alarm watch as set forth in claim 6, wherein the membrane and its carrier or an inside cover member are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto.
 8. In a watch with an electronically driven alarm, the watch comprising in combination of a watch casing, a watch movement contained therein, an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing, and a source battery adapted for energization of said oscillator circuit and contained within said casing, the alarm comprising an oscillatory membrane and a piezo-electric or electro-strictive element fixedly attached to said membrane and electrically connected through said switch with said oscillation circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and fixedly mounted at its peripheral zone by said back cover which is provided with a contact terminal connected through a lead with said element.
 9. Alarm watch as set forth in claim 8, wherein said membrane, together with said piezo-electric or electro-strictive element and a membrane carrier, is electrically so connected with the alarm oscillator circuit as to be easily detachable therefrom, and thus equally from the watch unit.
 10. Alarm watch as set forth in claim 8, wherein said membrane is made of a conductive metal foil.
 11. Alarm watch as set forth in claim 8, wherein said membrane carrier acts as a part of water-proofing members of the watch unit.
 12. Alarm watch as set forth in claim 8, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.
 13. Alarm watch as set forth in claim 8, wherein said membrane acts as a part of water-proofing members of the watch unit.
 14. Alarm watch as set forth in claim 13, wherein the membrane and its carrier or an inside cover member are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto.
 15. In a watch with an electronically driven alarm, the watch comprising in combination of a watch casing, a watch movement contained therein, an alarm switch controlled thereby, an electronic alarm oscillator circuit contained within said casing, and a source battery adapted for energization of said oscillator circuit and contained within said casing, the alarm comprising an oscillatory membrane and a piezo-electric or electro-strictive element fixedly attached to said membrane and electrically connected through said switch with said oscillation circuit and said battery for being energized therefrom, said membrane being arranged in a space defined by and between a perforated back cover and the watch movement and made of a conductive metal foil, said element comprising a pair of electrodes and said watch being characterized by that one of said electrodes is conductively connected with said membrane.
 16. Alarm watch as set forth in claim 15, wherein said back cover is formed with a number of projections for prevention of a tight contact with human skin.
 17. Alarm watch as set forth in claim 15, wherein said membrane acts as a part of water-proofing members of the watch unit.
 18. Alarm watch as as set forth in claim 17, wherein the membrane and its carrier or an inside cover member are arranged substantially in proximate position with each other as for preventing excess distortion of the membrane when unintentional high pressure be applied thereto. 